Spark-plug



F. W. BEALL, JR'.-

SPARK PLUG.

APPLlcAlloN FILED N0v.25. 1919.

anw/whoa Patented July 20, 1920.

l flor/Meij Jr. a citizen of the UNITED ,STATES FLETCHER. w. BELLI., Jn., or M'QCALLA, ALABAMA.

sunk-PLUG.

Specification of Letters Patent.

Patented July 20,1920.

Application med November 25. 1919. Serial No. 840.524.

To-aZZ Lv/Yom. it may concern.'

Beit known that I, FLETCHER W. BEALL,

United States, residin at McCalla,-in the county of Jefferson an State of Alabamal,fhave invented new and useful Improvements in Spark-Plugs, of which the following is a specification.

The object of my present sole inventionis the provision of a sparkplu that is simple and inexpensive in construction, is provided with means for intensifying the spark in such manner that the spark is visible, is adequately insulated, and is practically unbreakable under the action of either heat, blows or shock.

To the attainment of the foregoing the invention consists in the improvement as hereinafter described and definitely claimed.-

In the accompanying drawing, hereby made a part hereof: A

Figure 1 is a side elevation of my novel spark plug. l

Fig. 2 is a diametrical section of the same.

Similar numerals of reference designate corresponding parts in both views of the drawings.

The shell 1 of the spark plug is of metal, is provided with the usual threaded portion 2 and exteriorly angular portion 3, and is equipped at its inner end with a ground electrode 4.

At 5 is the main electrode of the plug, the inner end of said electrode being arranged adjacent to and spaced from the end of the electrode 4, in the ordinary well known manner. On the main electrode 5 is an outwardly tapered portion 6 that is wedged through an aperture in the compression nut 7 and merges into la threaded shank 8 that extends about the distance illustrated above the tapered portion. Before being wedged as stated in the compression nut 7 the electrode 5 is wrapped with sheet mica, as indicated by 9.

At 10 is the top insulator post of the plug, which post is formed in one piece of fiber,

is provlded with a diametrical opening 11,`

and has its lower portion a taper bore 12 to fit over the tapered portion 6, and also has above said taper bore 12 a threaded bore 13 that receives and engages the upper threaded end portion of the main electrode 5, whereby when the post 10 is turned downwardly on the electrode, the parts will be tightly and strongly connected together. The upper end of the main electrode 5 extends a slight distance into the opening 11.

Threaded in the upper end portion of the post v10, is a terminal 14, designed to be connected in the ordinary or any other well known manner with the source of electrical current supply. The said terminal 14 is dcsigned to be adjustedin the post 10 to increaseor diminish the size of the gap between the terminal and the upper end ofthe electrode 5. Theprovision.. of the said gap,

serves to intensify the spark afforded between the electrodes 4 and 5, and manifestly the spark at the gap is always visible through the opening 11.

Having described my invention, what I claim and desire to secure by Letters-Patent, is:

A spark plug comprising a shell equipped with an electrode, a compression nut, a main lelectrode having an outwardly tapered portion-wrapped with sheet mica and wedged in thecompression nut and also having a threaded shank outwardly beyond said tapered portion, a post of fiber opposed at its inner end to the compression nut and having a taper bore receiving the tapered portion of the main electrode and also having a threaded bore receiving and engaging the threaded Lshank of the main electrode and further havlng a diametrical opening, and a terminal adjustable in the upper, portion of the post and extending into the openingr thereof and arranged within said opening in spaced relation to the outer end of the main electrode.

In testimony whereof I affix my signature.

FLETCHER WV. BEALL, Jn. 

